Simplify the following expression: ${-6r+4+5-r}$
Solution: Rewrite the expression to group the ${r}$ terms and numeric terms: $ {-6r - r} + {4 + 5}$ Combine the ${r}$ terms: $ {-7r} + {4 + 5}$ Combine the numeric terms: $ {-7r} + {9}$ The simplified expression is $-7r+9$